The present invention relates to rigid awnings that usually are installed over windows.
Awnings have been used for centuries to enhance aesthetic appeal of building exteriors and protect building interiors from excessive gain of solar heat through windows. Shading windows with awnings is one of the known methods of increasing energy efficiency of buildings. By lowering temperature inside the building during air conditioning seasons, awnings create savings in cooling energy and also may help lower cost of mechanical cooling equipment. These benefits of awnings are described in a report “Awnings in Residential Buildings” that was initiated by the Professional Awning Manufacturers Association (PAMA) and issued in September 2007 by the Center for Sustainable Building Research of the University of Minnesota with participation by the Windows and Glazings Program at Lawrence Berkeley National Laboratory (LBNL). It is obvious that the same benefits are available for commercial and industrial buildings.
The same report notes that because awnings block desirable passive gain of solar heat during the heating season, the highest energy savings are achieved if awnings are kept in place in summer and removed or retracted in winter.
It is also advisable to remove or retract awnings in anticipation of high wind or storm conditions to reduce the load on and avoid possible destruction of the awnings and the associated building.
Because removing awnings for the winter season or before a storm is difficult and inconvenient, it is desirable to use retractable awnings. Such awnings are well known in the industry and usually are made of fabric. A retractable fabric awning is retracted by rolling the fabric up onto a roller rotatably attached to the building.
Even though retractable fabric awnings have been in use for decades, they are not sufficiently durable, as they require periodic replacement of the fabric; they are not able to withstand high winds or any significant snow or ice load.
The prior art also includes retractable or adjustable rigid awnings. One of such adjustable awnings is described in U.S. Pat. No. 2,791,009 to Wagner. It is a louver type awning where louvers are operated by a link mechanism. Among the disadvantages of such awning is the existence of an excessive number of movable parts subject to weather elements, which makes it prone to malfunction. Also, such awning cannot be retracted for the winter season and therefore inevitably creates shade when it is not needed. A collapsible rigid awning is described in U.S. Pat. No. 6,202,363 to Chang. It may be collapsed when shade is not required, however its operating mechanism is complicated, consisting of many movable parts subject to weather elements, and also is prone to malfunction. In addition, such awning does not lend itself to being used in any intermediate position between the fully extended and fully collapsed positions. Furthermore, when in the collapsed position, it requires additional space width-wise approximately equal to the length of its panels. Another type of retractable rigid awnings is available on the market in the form of roll-up awnings. Such awning consists of narrow aluminum strips connected to each other with ropes or bands and is retracted by rolling these strips up onto a roller, similar to fabric retractable awnings. This design does not allow for any side panels that may be desired, has many small movable parts and requires constant tension to be applied to the connecting ropes or bands to maintain the awning in a taut condition, which reduces the awning's durability.